绕二维对称水翼的通气空泡流数值研究

本文通过有限体积离散方法求解Reynolds平均Navler—Stokes方程，采用VOF法追踪气一液两相交界面。研究了在高压低速来流，即本质上不发生自然空化的条件下，绕二维对称水翼的非定常通气空泡流动。分析了物理参数——通气方向角和攻角，对通气空泡外形、稳定性及水动力参数的影响。计算结果表明：在通气空泡的形成过程中，通气方向角存在着一个临界值，使得空泡形态由片状空泡过渡到超空泡；特定的参数组合将会诱发空泡表面出现波动现象。而且，当攻角做周期性变化时，水动力参数的变化也随之满足周期性规律，且出现阶段性振荡。

Numerical investigation of ventilated cavitating flow around a 2D symmetry foil

By finite volume method in framework of the time-dependent Reynolds-Averaged Navier-Stokes equations,the unsteady process of ventilated cavities has been studied around a 2D symmetry hydrofoil without natural cavitation physically.The computation is carried out by using the volume of fluid(VOF) technique to track the gas-liquid two-phase interface.The authors investigate the influence of physical parameters-ventilation direction and angle of attack on the shape,instability and hydrodynamic characteristic of ventilated cavities.The results of simulation indicate that there is a critical value for ventilation direction to transfer sheet cavity into supercavity.A special combination of parameters can induce an interface fluctuation.Moreover,the hydrodynamic parameters vary with the angle of attack periodically and oscillate intermittently.